1. Field of the Invention
The present invention relates to an orientation-adjusting devices for vehicle head lights, and especially to an orientation-adjusting device for adjusting the projecting angle of a vehicle head light.
2. Description of Related Art
Referring to FIG. 1, a perspective view of a head light 900 generally used in a car is illustrated. The head light assembly 900 is an integrally-formed housing encasement 910 with a main light 920 and an indicator 930 installed therein. The main light 920 has a reflecting mask 922 which can be adjusted leftwards, rightwards, upwards or backwards. Furthermore, two mounting holes 912 as shown in FIG. 2 are formed at a rear lateral side of the housing encasement 910. The reflecting mask 922 in the housing encasement 910 is formed with a buckling hole 924 corresponding with respect to the mounting hole 912.
In a prior art, Taiwanese Utility Model Application No. 89214252 filed by the inventor of the present invention, an adjuster for adjusting the orientation of the reflecting mask 922 of the head light assembly 900 of a car is disclosed. However, in practical production and applications, it has been discovered that there are a couple of defects in the orientation adjuster as described in the following:
When an active unit 20 is rotated through an angle until the front end of a driven screw rod 30 can not be further retracted, i.e., when the rear end surface of a circular protrusion 32 of the driven screw rod 30 resists against the front end surface of a driven unit 40, as shown in FIG. 3, it is possible that a vertical portion 54 of a cover 50 will be damaged once the driving member 20 is subject to over-rotation; the torque of the rotated active unit 200 that causes the damage is a destructive one. Similarly, when the active unit 20 is rotated along a reverse direction, until the front end of the driven screw rod 30 can not be moved forward any further (i.e. when the front end of the circular protrusion 32 of the driven screw rod 30 withstands the inner wall of a housing unit 10), it is possible that the driven screw rod 30 will be destroyed once the driving member 20 is subject to over-rotation. In such a situation, the torque of the active unit 20 that causes the damage is generally referred to as a destructive one.
In fact, not only the orientation adjuster has the foregoing problem, but also a general orientation adjuster suffers the same problem. Therefore, the specification of the general adjuster must list the value of the break in torque and break out torque to act as a reminder to the user from applying too much twisting force thereto. Moreover, the adjusters must be designed to tolerate up to the break in torque and break out torque. For the adjuster of the prior art, in order that the vertical portion 54 of the cover 50 and the driven screw rod 30 must be tolerate up to the destructive torque, it is required to enlarge the thickness of the vertical portion 54 and the diameter of the driven screw rod 30. It increases not only the cost of materials, but also the volume of the orientation adjuster.
In the aforesaid head light assembly 900, other than the mounting hole 912, the housing encasement 910 is a closed structure without any slit. Therefore, when the adjuster device of the prior art is being mounted in position by first passing a cylindrical portion 11 with a buckling protrusion 13 through the mounting hole 912, then at the time of compressing an elastic pad 12, buckling a buckle 33 of the driven screw rod 30 into the buckling hole 924, and finally rotating the whole adjuster until it reaches the predetermined position the housing encasement 910 becomes air-tight to prevent vapor from entering into the housing encasement 910 and thus keep mist from being formed therewithin, which impels light to emit out, and further preventing bulbs of the main light 920 and the indicator 930 from being damaged by humidity.
In the head light assembly 900 with the aforesaid structure, when the driving member 20 is over-rotated in one direction, the over-retracted buckle 33 would possibly destroy the buckling hole 924 and break the reflecting mask 922. Similarly, when the driving member 20 is over-rotated in the other direction, the reflector 922 may be damaged by the over-inserted buckle 33. In the above situations, since the housing encasement 910 is a closed structure and the reflector 922 cannot be replaced, the whole of head light assembly 900 must be replaced as a whole. In other words, when the conventional orientation adjuster is damaged by screw-in or screw-out destroyed, not only the adjuster itself is destroyed, the whole lamp assembly is ruined.
As described above, when the head light assembly 900 is mounted with the orientation adjuster of the prior art, the housing encasement 910 must be completely air-tight. However, in the orientation adjuster of the prior art, the driven screw rod 30 is installed and screwed to the first hole 14 of the cylindrical portion 11, and thus the screwing structure cannot satisfactorily assure the air tightness of the housing 910. Therefore, vapor might be allowed to enter into the housing encasement 910, and thus, the interior of the housing encasement 910 is easy to have mist formed therein, and the main light 920 or the indicator 930 is easily damaged by moisture.
In addition, the conventional adjuster has the same defects. In order to assure the airtightness, there are conventional orientation adjusters equipped with sealing rubber at its front-most end (not shown). However, as the interior of the head light assembly 900 is often at a high temperature due to heat generated by the bulbs, the rubber exposed to such a high temperature is easily worn and needs to be often replaced.
In the orientation adjuster of the prior art, a threaded section 31 of the driven screw rod 30 must be screwed to the elliptical hole 14 of the cylindrical section 1, and therefore, the length of the threaded section 31 must be approximately equal to twice the length of the hole 14. This limits the further reduction of the volume of the orientation adjuster.
The present invention is accomplished in order to improve the defects disclosed in the prior art. It is therefore an object of the present invention, to provide an orientation adjusting device for a vehicle head light without the confinement of the destructive torque, so that no damage to the orientation adjusting device will occur even if it is over-rotated.
It is another object of the present invention to provide an orientation-adjusting device for a vehicle head light that the airtightness can be satisfactorily achieved.
A further object of the present invention is to provide an orientation-adjusting device for a vehicle head light that can be used with a longer lifetime.
It is still another object of the present invention to provide an orientation-adjusting device for a vehicle head light with a reduced volume.
To achieve the above objectives, the present invention provides an orientation-adjusting device for a vehicle head light comprising a housing encasement, an active unit, a driven unit, a cover, driven screw rod, an elastic unit, and an elastic sealing unit. The housing encasement is installed with an elliptical hole and an axial hole. The active unit has an axial portion axially installed at the axial hole and a gear portion located in the housing encasement. The driven unit has another gear portion engaged with the gear portion of the active unit, and an axially-formed penetrating hole, wherein the penetrating hole includes a threaded hole section near the active unit and a threadless hole section remotely away from the active unit. The cover is installed on the housing encasement to cover the interior thereof and prevent the driven unit from projecting out therefrom. The driven screw rod has one end formed with a threaded section screwed to the threaded hole section of the driven unit, and the other end formed with an elliptical cross section which is capable of protruding out of the elliptical hole of the housing encasement where it is connected with the car illuminator, wherein the base portion of the elliptical cross section is formed with a circular protrusion, and a threadless cylindrical section is formed between the circular protrusion and the threaded section. The elastic unit is installed between the circular protrusion of the driven screw rod and the driven unit. When the active unit is over-rotated in one direction so that the threaded section of the driven screw rod and the threaded hole section of the driven unit, due to the threaded hole section of the driven unit, are completely inserted in the cylindrical section of the driven screw rod; and when the threaded section of the driven screw rod is completely inserted into the threadless hole section of the driven unit and falls therefrom; the elastic unit praides and elastic force for re-screwing the threaded section of the driven screw rod to the threaded hole section of the driven unit as the active unit is roated in a reverse direction. The elastic sealing unit is installed between the circular protrusion of the driven screw rod and the elliptical hole of the housing for preventing gas from passing through the elliptical hole. When the active unit is over-rotated along a direction so that the threaded section of the driven screw rod is separated from the threaded hole section of the driven unit, the elastic sealing unit provides an elastic force for re-screwing the threaded section of the driven screw rod to the threaded hole section of the driven unit.
The various objects and advantages of the present invention can be fully understood by reading the following detailed description with reference made to the accompanying drawings, but the present invention is not understood to be limited by them.